1. Technical Field
The disclosure relates to an image sensor, an imaging device, an endoscope, and an endoscope system that are configured to image a subject to generate image data of the subject.
2. Related Art
Conventionally, it is known that a plurality of light-shielded pixels called optical black (OB) pixels is provided to obtain a black reference level in an imaging device including an image sensor such as a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS) (for example, see JP 2012-235193 A). In this technique, OB pixels are provided over a plurality of rows and a plurality of columns, and a black reference signal which determines a black level in an OB region is subtracted from an imaging signal in an effective region which is not light-shielded. By doing so, a noise component included in the imaging signal in the effective region is eliminated.